Phosphodiesterase 10a inhibitors

Abstract

A phosphodiesterase 10A inhibitor serving as an effective prophylactic or therapeutic agent for Parkinson's disease, Huntington's disease, Alzheimer's disease, and schizophrenia. The PDE10A inhibitor contains as an active ingredient a pyrazolo[1,5-a]pyridine derivative represented by the following general formula: wherein R 1 and R 2 are each independently a hydrogen atom or a lower alkyl group having 1 to 4 carbons; and R 3 is a hydrogen atom, a lower alkyl group having 1 to 4 carbons, or a lower alkoxyl group having 1 to 3 carbons.

1 . A phosphodiesterase 10A inhibitor containing as an active ingredient a pyrazolo[1,5-a]pyridine derivative represented by the following general formula (1):  
     
       
         
         
             
             
         
       
     
     wherein R 1  and R 2  are each independently a hydrogen atom or a lower alkyl group having 1 to 4 carbons; and R 3  is a hydrogen atom, a lower alkyl group having 1 to 4 carbons, or a lower alkoxyl group having 1 to 3 carbons.  
   
   
       2 . The phosphodiesterase 10A inhibitor according to  claim 1 , wherein the compound represented by the general formula (1) is 3-isobutyryl-2-isopropyl pyrazolo[1,5-a]pyridine.  
   
   
       3 . A therapeutic or prophylactic agent for Parkinson's disease containing as an active ingredient the phosphodiesterase 10A inhibitor according to  claim 1 .  
   
   
       4 . A therapeutic or prophylactic agent for Huntington's disease containing as an active ingredient the phosphodiesterase 10A inhibitor according to  claim 1 .  
   
   
       5 . A therapeutic or prophylactic agent for Alzheimer's disease containing as an active ingredient the phosphodiesterase 10A inhibitor according to  claim 1 .  
   
   
       6 . A therapeutic or prophylactic agent for schizophrenia containing as an active ingredient the phosphodiesterase 10A inhibitor according to  claim 1 .  
   
   
       7 . A therapeutic or prophylactic agent for Parkinson's disease containing as an active ingredient the phosphodiesterase 10A inhibitor according to  claim 2 .  
   
   
       8 . A therapeutic or prophylactic agent for Huntington's disease containing as an active ingredient the phosphodiesterase 10A inhibitor according to  claim 2 .  
   
   
       9 . A therapeutic or prophylactic agent for Alzheimer's disease containing as an active ingredient the phosphodiesterase 10A inhibitor according to  claim 2 .  
   
   
       10 . A therapeutic or prophylactic agent for schizophrenia containing as an active ingredient the phosphodiesterase 10A inhibitor according to  claim 2.